Refrigerator and method for controlling the refrigerator

ABSTRACT

A refrigerator and method for controlling the refrigerator including a plurality of storage chambers, in which a defrosting operation is executed based upon operation conditions of the storage chambers, to minimize a degradation in cooling efficiency which may occur when a defrosting operation is carried out in an independent manner for each storage chamber. When the refrigerator control method is applied to a refrigerator including a plurality of storage chambers, and a plurality of heaters to defrost the storage chambers, respectively, the refrigerator control method includes determining whether defrosting is required, for each of the plurality of the storage chambers, and selecting, from the plurality of the storage chambers, storage chambers having similar temperature ranges, when if is determined that defrosting is required, and controlling the plurality of the heaters to collectively defrost the selected storage chambers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Applications No. 10-2005-0122762, filed on Dec. 13, 2005 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a refrigerator. More particularly, to a defrosting apparatus and method of a refrigerator for removing frost formed on the surface of an evaporator.

2. Description of the Related Art

Refrigerators operate to decrease the internal temperature of a storage chamber thereof, through a cooling cycle performing compression, condensation, expansion, and evaporation of a refrigerant, and thus, to store food in a fresh state at a low temperature. A conventional refrigerator includes a compressor which compresses a low-temperature/low-pressure gaseous refrigerant, to increase the temperature and pressure of the refrigerant to a high-temperature/high-pressure gas state, a condenser which heat-exchanges the refrigerant emerging from the compressor with ambient air, to condense the refrigerant, an expansion device which reduces the pressure of the condensed refrigerant emerging from the condenser, and an evaporator which heat-exchanges the pressure-reduced refrigerant emerging from the expansion device with air present in a storage chamber to cause the refrigerant to be evaporated while absorbing heat from the air in the storage chamber.

A blowing fan is also arranged near the evaporator, to blow cold air present around the evaporator into the interior of the storage chamber. In accordance with operation of the blowing fan, an air circulation cycle is established. That is, air heated due to heat exchange thereof in the storage chamber is forced to move toward the evaporator, and is then cooled. The cooled air around the evaporator is again supplied to the interior of the storage chamber, to reduce the internal temperature of the storage chamber. During such an air circulation, frost is formed on the surface of the evaporator due to moisture contained in air flowing from the storage chamber toward the evaporator. The frost on the evaporator surface causes a degradation in cooling efficiency because it interferes with the evaporation function of the evaporator and the flow of cold air. For this reason, it is necessary to perform a defrosting operation to remove the frost on the evaporator surface.

The defrosting operation in the refrigerator is carried out using a heater arranged near the evaporator, as a heating means to melt frost on the evaporator surface. During this defrosting operation, it is impossible to achieve a normal evaporation function (i.e., a cold air generation function) of the evaporator. For this reason, it is desirable to minimize the defrosting operation time or the frequency of the defrosting operation, in order to enhance the cooling efficiency of the refrigerator.

SUMMARY OF THE INVENTION

Accordingly, it is an aspect of the present invention to provide a method for controlling a refrigerator having a plurality of storage chambers, which groups a part of the storage chambers, to selectively enable a defrosting operation to be collectively performed only for the grouped storage chambers, or to be simultaneously performed for all storage chambers, thereby minimizing a degradation in the cooling efficiency of the refrigerator which occurs when the defrosting operation is carried out in an independent manner for respective storage chambers.

Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.

These and/or other aspects of the present invention are achieved by providing a method for controlling a refrigerator including a storage space divided into a first storage chamber, a second storage chamber, a third storage chamber, and a fourth storage chamber, the method including executing a simultaneous defrosting operation for all the storage chambers when at least one of the first storage chamber and the third storage chamber is in an overload condition, and selectively executing a simultaneous defrosting operation or an alternate defrosting operation in accordance with a set temperature of the second storage chamber or a set temperature of the fourth storage chamber when neither the first storage chamber nor the third storage chamber is in the overload condition.

According to an aspect of the present invention, the first storage chamber is a refrigerating chamber, and the third storage chamber is a freezing chamber.

According to an aspect of the present invention, the set temperatures of the second and fourth storage chambers is higher than 0° C. or not higher than 0° C. Accordingly, each of the second and fourth storage chambers may be selectively used as a refrigerating chamber or a freezing chamber.

According to an aspect of the present invention, the refrigerator includes a basic defrosting mode in which a defrosting operation for the first and second storage chambers and a defrosting operation for the third and fourth storage chamber are alternately executed. When a last defrosting operation of a latest one of previous basic defrosting modes is the defrosting operation for the third and fourth storage chamber, one of the simultaneous defrosting operation and the alternate defrosting operation may be selectively executed, in accordance with the set temperature of the fourth storage chamber. When the last defrosting operation of a latest one of previous basic defrosting modes is the defrosting operation for the first and second storage chamber, one of the simultaneous defrosting operation and the alternate defrosting operation may be selectively executed in accordance with the set temperature of the second storage chamber.

According to an aspect of the present invention, the refrigerator includes first to fourth fans to circulate air through the first to fourth storage chambers, respectively. When the first fan which circulates air through the first storage chamber operates continuously for a first predetermined time after a second predetermined time has elapsed after completion of the defrosting operation for the first and second storage chambers or the defrosting operation for the third and fourth storage chambers, it is determined that the first storage chamber is in an overload condition. When a compressor operates continuously for a third predetermined time after a fourth predetermined time has elapsed after completion of the defrosting operation for the first and second storage chambers, it is determined that the third storage chamber is in an overload condition.

The simultaneous defrosting operation is executed when the set temperature of the second storage chamber is not higher than 0° C., or when the set temperature of the fourth storage chamber is higher than 0° C.

When the set temperature of the second storage chamber is not higher than 0° C., the simultaneous defrosting operation is executed for all the first storage chamber, the second storage chamber, the third storage chamber, and the fourth storage chamber. When the set temperature of the fourth storage chamber is higher than 0° C., the simultaneous defrosting operation is executed only for the first storage chamber, the second storage chamber, and the fourth storage chamber.

The alternate defrosting operation is executed when the set temperature of the second storage chamber is higher than 0° C., or when the set temperature of the fourth storage chamber is not higher than 0° C.

When the set temperature of the fourth storage chamber is not higher than 0° C., the alternate defrosting operation is executed in such a manner that the defrosting operation for the first and second storage chambers alternates with the defrosting operation for the third and fourth storage chambers. When the set temperature of the second storage chamber is higher than 0° C., the alternate defrosting operation may be executed in such a manner that the defrosting operation for the third and fourth storage chambers alternates with the defrosting operation for the first and second storage chambers.

The alternate defrosting operations for the first and second storage chambers and the third and fourth storage chambers when the set temperature of the fourth storage chamber is not higher than 0° C. is executed in such a manner that the defrosting operation for the first and second storage chambers is first executed. The alternate defrosting operations for the third and fourth storage chambers and the first and second storage chambers when the set temperature of the second storage chamber is higher than 0° C. is executed in such a manner that the defrosting operation for the third and fourth storage chambers is first executed.

It is another aspect of the present invention to provide a method for controlling a refrigerator including a storage space divided into a first storage chamber, a second storage chamber, a third storage chamber, and a fourth storage chamber, the method including executing a simultaneous defrosting operation for all the storage chambers when at least one of the first storage chamber and the third storage chamber is in an overload condition, executing the simultaneous defrosting operation for all the storage chambers when neither the first storage chamber nor the third storage chamber is in the overload condition, and a set temperature of the second storage chamber is not higher than 0° C., simultaneously executing defrosting operations for the first, second and fourth storage chambers when neither the first storage chamber nor the third storage chamber is in the overload condition, and a set temperature of the fourth storage chamber is higher than 0° C., alternately executing a defrosting operation for the first and second storage chambers and a defrosting operation for the third and fourth storage chambers, when neither the first storage chamber nor the third storage chamber is in the overload condition, and a set temperature of the fourth storage chamber is not higher than 0° C.; and alternately executing the defrosting operation for the third and fourth storage chambers and the defrosting operation for the first and second storage chambers when neither the first storage chamber nor the third storage chamber is in the overload condition, and a set temperature of the second storage chamber is higher than 0° C.

It is another aspect of the present invention to provide a method for controlling a refrigerator including a storage space divided into a refrigerating chamber, an auxiliary refrigerating chamber, a freezing chamber, and an auxiliary freezing chamber, the method including executing a simultaneous defrosting operation for all the storage chambers when at least one of the refrigerating chamber and the freezing chamber is in an overload condition, executing the simultaneous defrosting operation for all the storage chambers when neither the refrigerating chamber nor the freezing chamber is in the overload condition, and a set temperature of the auxiliary refrigerating chamber is not higher than 0° C.; simultaneously executing defrosting operations for the refrigerating chamber, the auxiliary refrigerating chamber, and the auxiliary freezing chamber when neither the refrigerating chamber nor the freezing chamber is in the overload condition, and a set temperature of the auxiliary freezing chamber is higher than 0° C., alternately executing a defrosting operation for the refrigerating chamber and the auxiliary refrigerating chamber and a defrosting operation for the freezing chamber and the auxiliary freezing chamber when neither the refrigerating chamber nor the freezing chamber is in the overload condition, and a set temperature of the auxiliary freezing chamber is not higher than 0° C., and alternately executing the defrosting operation for the freezing chamber and the auxiliary freezing chamber and the defrosting operation for the refrigerating chamber and the auxiliary refrigerating chamber when neither the refrigerating chamber nor the freezing chamber is in the overload condition, and a set temperature of the auxiliary refrigerating chamber is higher than 0° C.

It is yet another aspect, of the present invention to provide a method for controlling a refrigerator including a plurality of storage chambers, and a plurality of heaters respectively adapted to defrost the plurality of storage chambers, the method including determining whether defrosting is required, for each of the plurality of the storage chambers, and selecting, from the plurality of the storage chambers, storage chambers having similar temperature ranges, when it is determined that defrosting is required, and controlling the plurality of the heaters to collectively defrost the selected storage chambers.

The determination of whether defrosting is required for each of the plurality of the storage chambers is made based on at least one of a previous defrosting operation for the storage chamber, an overload condition of the storage chamber, and an operation condition of the storage chamber.

The plurality of the storage chambers includes a first storage chamber to provide storage in a refrigerating state, a second storage chamber to selectively provide storage in a refrigerating state or storage in a freezing state, a third storage chamber to providestorage in a refrigerating state, and a fourth storage chamber to selectively provide storage in a refrigerating state or storage in a freezing state.

According to an aspect of the present invention, a defrosting operation for the first and second storage chambers and a defrosting operation for the third and fourth storage chambers are alternately executed in an alternate defrosting mode. According to an aspect of the present invention, a simultaneous defrosting operation for all the first through fourth storage chambers is executed in a simultaneous defrosting mode.

According to an aspect of the present invention, one of the simultaneous defrosting mode and the alternate defrosting mode is selectively executed based upon a set temperature of the fourth storage chamber when the defrosting operation for the third and fourth storage chambers was executed in a latest one of previous alternate defrosting modes. Further, one of the simultaneous defrosting mode and the alternate defrosting mode is selectively executed based upon a set temperature of the second storage chamber when the defrosting operation for the first and second storage chambers was executed in the latest previous alternate defrosting mode.

According to an aspect of the present invention, the alternate defrosting mode is to alternately execute the defrosting operation for the third and fourth storage chambers and the defrosting operation for the first and second storage chambers when the fourth storage chamber is used for storage in a freezing state, or when the second storage chamber is used for storage in a refrigerating state.

According to an aspect of the present invention, the defrosting operation for the third and fourth storage chambers is first executed in the alternate defrosting mode next to the latest previous defrosting mode when the defrosting operation for the first and second storage chambers was executed in the latest previous defrosting mode. The defrosting operation for the first and second storage chambers is first executed in the alternate defrosting mode next to the latest previous defrosting mode when the defrosting operation for the third and fourth storage chambers was executed in the latest previous defrosting mode.

It is another aspect of the present invention to provide a refrigerator including a plurality of storage chambers to store food therein, a plurality of heaters to defrost the plurality of storage chambers, respectively, and a controller to determine whether defrosting is required for each of the plurality of storage chambers, to selectively group storage chambers together which have a same temperature range and to control the heaters to collectively defrost the grouped storage chambers when it is determined that defrosting is required.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a perspective view illustrating a refrigerator having a plurality of storage chambers according to an embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating configurations of the multiple storage chambers in the refrigerator shown in FIG. 1, and a cooling cycle of the refrigerator according to an embodiment of the present invention;

FIG. 3 is a block diagram illustrating a control system of the refrigerator shown in FIGS. 1 and 2, according to an embodiment of the present invention; and

FIG. 4 is a flow chart illustrating a method for controlling a refrigerator having a plurality of storage chambers, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.

First, an embodiment of the present invention will be described with reference to FIGS. 1-4. FIG. 1 is a perspective view illustrating a refrigerator having a plurality of storage chambers according to an embodiment of the present invention. As shown in FIG. 1, the refrigerator 100 comprises four independent storage chambers R, CR, F, and CF which are opened or closed by doors 102R, 102CR, 102F, and 102CF provided for the storage chambers R, CR, F, and CF, respectively. In the present invention, the number of the storage chambers is not limited to four, as described above. That is, the present invention may be applied to any refrigerator, as long as the refrigerator includes at least one storage chamber, in addition to a freezing chamber and a refrigerating chamber.

FIG. 2 is a schematic diagram illustrating configurations of the multiple storage chambers in the refrigerator shown in FIG. 1, and a cooling cycle of the refrigerator, according to an embodiment of the present invention. As shown in FIG. 2, four storage chambers, , the storage chambers R, CR, F, and CF, are provided in the refrigerator. The storage chamber R is a first storage chamber functioning as a refrigerating chamber, the storage chamber CR is a second storage chamber functioning as an auxiliary refrigerating chamber, the storage chamber F is a third storage chamber functioning as a freezing chamber, and the storage chamber CF is a fourth storage chamber functioning as an auxiliary freezing chamber. When the refrigerator is provided with only one auxiliary storage chamber CR or CF, in addition to the refrigerating chamber R and freezing chamber F, the refrigerating chamber R, freezing chamber F, and auxiliary storage chamber CR or CF may be classified into first, second, and third storage chambers, respectively.

Each storage chamber R, CR, F or CF includes an evaporator 206R, 206CR, 206F or 206CF, a fan 208R, 208CR, 208F or 208CF, a defrosting heater 210R, 210CR, 210F or 210CF, a defrosting sensor 212R, 212CR, 212F or 212CF, and a storage chamber temperature sensor 214R, 214CR, 214F or 214CF. Each evaporator 206R, 206CR, 206F or 206CF and each fan 208R, 208CR, 208F or 208CF are provided for air circulation through an associated one of the storage chambers R, CR, F and CF. Each defrosting heater 210R, 210CR, 210F or 210CF defrosts a surface of an associated one of the evaporator 206R, 206CR, 206F or 206CF. Each defrosting sensor 212R, 212CR, 212F or 212CF detects a surface temperature of an associated one of the evaporator 206R, 206CR, 206F or 206CF during a defrosting operation, in order to enable determination of the point of time when an associated one of the defrosting heaters 210R, 210CR, 210F or 210CF is to be turned off, based on the detected surface temperature. Each storage chamber temperature sensor 214R, 214CR, 214F or 214CF detects an internal temperature of an associated one of the storage chambers R, CR, F, and CF.

In the refrigerator according to the embodiment of the present invention as shown in FIG. 2, for example, the refrigerating chamber R and freezing chamber F store food in a refrigerating state and in a freezing state, respectively, same as refrigerating and freezing chambers in conventional refrigerators. Each of the auxiliary refrigerating chamber CR and auxiliary freezing chamber CF comprises a storage temperature range and cooling operation characteristics different from those of the refrigerating chamber R and freezing chamber F. That is, a target internal temperature of each of the auxiliary refrigerating chamber CR and auxiliary freezing chamber CF (i.e., a temperature desired by the user) may be freely set to be higher than or not higher than 0° C. In the present invention, it is unnecessary to essentially use the two auxiliary storage chambers CR and CF. When necessary, only one auxiliary storage chamber may be used. Alternatively, three or more auxiliary storage chambers may also be used.

FIG. 3 is a block diagram illustrating a control system of the refrigerator shown in FIGS. 1 and 2. In FIG. 3, a controller 302 is illustrated which controls the overall operation of the refrigerator. The defrosting sensors 212R, 212CR, 212F and 212CF, and storage chamber temperature sensors 214R, 214CR, 214F and 214CF are connected to an input of the controller 302. The fans 208R, 208CR, 208F and 208CF, defrosting heaters 210R, 210CR, 210F and 210CF, and compressor 202 are connected to an output of the controller 302. The controller 302 receives information as to evaporator surface temperatures from the defrosting sensors 212R, 212CR, 212F and 212CF and information as to storage chamber temperatures from the storage chamber temperature sensors 214R, 214CR, 214F and 214CF, and controls the compressor 202, a condenser 204, fans 208R, 208CR, 208F and 208CF, and defrosting heaters 210R, 210CR, 21 OF and 210CF, based on the received information, to cause the refrigerator to perform desired cooling and defrosting operations.

Since the refrigerator according to the embodiment of the present invention includes the auxiliary refrigerating chamber CR and auxiliary freezing chamber CF in addition to typical refrigerating and freezing chambers, namely, the refrigerating and freezing chambers R and F, the defrosting operation of the refrigerator may frequently be performed when the defrosting pattern used in refrigerators having two typical storage chambers is applied to the refrigerator without any modification. Accordingly, a degradation in cooling efficiency may occur. Thus, the controller 302 performs a control operation for the defrosting operation, taking into consideration respective operation conditions of the four storage chambers R, CR, F, and CF, in order to minimize the defrosting operation time and the frequency of the defrosting operation, and thus, to maximize the cooling efficiency.

FIG. 4 is a flow chart illustrating a method for controlling a refrigerator having a plurality of storage chambers as described above, in accordance with an embodiment of the present invention. As shown in FIG. 4, the refrigerator control method executes a defrosting operation mode, taking into consideration a “previous defrosting operation condition” an “overload condition of the refrigerating or freezing chamber” and “operation conditions of the auxiliary refrigerating and freezing chambers”. That is, in accordance with the refrigerator control method according to an embodiment of the present invention, it is determined whether it is necessary to defrost a part or all of the storage chambers, based on the “previous defrosting operation condition” the “overload condition of the refrigerating or freezing chamber” and the “operation conditions of the auxiliary refrigerating and freezing chamber” for example. It is also determined whether there are storage chambers having similar temperature ranges. When there are storage chambers having similar temperature ranges, these storage chambers are grouped. For the grouped storage chambers, a defrosting operation is collectively carried out. In accordance with this refrigerator control method, it is possible to minimize a degradation in cooling efficiency which may occur when a defrosting operation is carried out in an independent manner for each storage chamber. In particular, in the refrigerator control method according to an embodiment of the present invention, all storage chambers are simultaneously defrosted when a particular one of the storage chambers, which is set to be a reference storage chamber, is determined to be in an overload condition. On the other hand, when it is determined that the reference storage chamber is not in an overload condition, the grouped storage chambers are collectively defrosted. For reference, “R”, “CR”, “F”, and “CF” in FIG. 4 designate the refrigerating chamber R, auxiliary refrigerating chamber CR, freezing chamber F, and auxiliary freezing chamber CF, respectively.

In accordance with the refrigerator control method, in operation 402, it is first determined whether a defrosting operation is required. When no defrosting operation is required (“NO” at operation 402), a cooling operation, which is currently required, is carried out without execution of a defrosting operation. Conversely, when a defrosting operation is required (“YES” at operation 402), the process moves to operation 404, where it is determined whether a freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) was executed in the previous defrosting operation (“YES” at operation 404), or a refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR) was executed in the previous defrosting operation (“NO” at operation 404). In a basic defrosting mode of the refrigerator according to the embodiment of the present invention shown in FIG. 2, for example, a defrosting operation is executed in the order of R/CR→F/CF→R/CR→F/CF.

A simultaneous defrosting operation or an alternate defrosting operation is selectively executed in accordance with associated conditions, to minimize execution of unnecessary defrosting operations. When all the four storage chambers R, CR, F, and CF are simultaneously defrosted every time a defrosting operation is required, there is a problem in that even the storage chamber or chambers requiring no defrosting operation are defrosted, thereby causing a degradation in cooling efficiency and an increase in electric power consumption.

When the previous defrosting operation is the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) or the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR), the simultaneous defrosting operation for all storage chambers (R/CR/F/CF) is executed when the refrigerating chamber R or freezing chamber F is in an overload condition (“YES” at operation 406 or operation 408) (operation 410).

The overload condition of the refrigerating chamber R corresponds to the case in which the refrigerating fan 208R operates continuously for approximately 2 hours or more from the point of time when the operating time of the compressor 202 accumulated after completion of the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) exceeds approximately 4 hours. The overload condition of the freezing chamber F occurs when the compressor 202 operates continuously for approximately 2 hours or more from the point of time when the operating time of the compressor 202 accumulated after completion of the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR) exceeds approximately 4 hours.

When a cooling condition change, other than the overload condition of the refrigerating chamber R, requiring a continuous operation of the refrigerating chamber fan 208R, for example, change of the set temperature of the refrigerating chamber R, occurs during checking of a 2-hour continuous operation of the refrigerating chamber fan 208R, the count value for the 2-hour continuous operation is initialized, in order to prevent the overload condition determination for the refrigerating chamber R from being influenced by the operation of the refrigerating chamber fan 208R according to the changed cooling condition. Similarly, when a cooling condition change, other than the overload condition of the freezing chamber F, requiring a continuous operation of the compressor 202, for example, change of the set temperature of the freezing chamber F, occurs during checking of a 2-hour continuous operation of the compressor 202, the count value for the 2-hour continuous operation of the compressor 202 is initialized, in order to prevent the overload condition determination for the freezing chamber F from being influenced by the operation of the compressor 202 according to the changed cooling condition.

The simultaneous defrosting operation (R/CR/F/CF) for all the refrigerating chamber R, auxiliary refrigerating chamber CR, freezing chamber F, and auxiliary freezing chamber CF is executed when the refrigerating chamber R or freezing chamber F is in an overload condition. The overload condition of the refrigerating chamber R or freezing chamber F means that the compressor 202 or refrigerating chamber fan 208R operates continuously for a predetermined time or more because the amount of food, to be cooled, in the refrigerating chamber R or freezing chamber F is large. Since a large amount of frost is formed in the refrigerating chamber R or freezing chamber F in such an overload condition, it may be determined that it is impossible to obtain sufficient air circulation in the overload condition even when the fans 208R and 208F operate continuously. Accordingly, when the refrigerating chamber R or freezing chamber F is in an overload condition, the simultaneous defrosting operation (R/CR/F/CF) for all the refrigerating chamber R, auxiliary refrigerating chamber CR, freezing chamber F, and auxiliary freezing chamber CF is executed at the point of time when a defrosting operation is required. The amount of frost formed in the overload condition is larger than that of frost formed in other conditions. For this reason, when alternate defrosting operations are executed in the order of F/CF→R/CR→F/CF→R/CR in the overload condition, each storage chamber is intermittently defrosted. As a result, each storage chamber is insufficiently defrosted, so that frost still remains in the storage chamber. This frost causes an increase in the temperature of the storage chamber. Therefore, in the overload condition, the simultaneous defrosting operation (R/CR/F/CF) for all storage chambers is executed, in order to enhance the defrosting efficiency.

When it is determined that the previous defrosting operation is the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) (“YES” at operation 404), neither the refrigerating chamber R nor the freezing chamber F is in an overload condition (“NO” at operation 406), and the set temperature of the auxiliary freezing chamber CF is higher than 0° C. (“NO” at operation 412), the simultaneous defrosting operation is executed only for the refrigerating chamber R, auxiliary refrigerating chamber CR, and auxiliary freezing chamber CF (414). A defrosting operation next to “F/CF” in the basic defrosting operation mode of R/CR→F/CF→R/CR→F/CF, namely, the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR), is executed when the previous defrosting operation is the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) (“YES” at operation 404), and neither the refrigerating chamber R nor the freezing chamber F is in an overload condition (“NO” at operation 406). When the set temperature of the auxiliary freezing chamber CF is higher than 0° C., although the internal temperature of the auxiliary freezing chamber CF is higher than 0° C., the temperature of the auxiliary freezing chamber evaporator 206CF is not higher than 0° C. Thus, frost is frequently formed on the surface of the auxiliary freezing chamber evaporator 206CF due to the temperature difference between the internal temperature of the auxiliary freezing chamber CF and the auxiliary freezing chamber evaporator 206CF. In the above conditions, accordingly, a defrosting operation for the auxiliary freezing chamber CF is executed together with the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR).

On the other hand, when the previous defrosting operation is the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) (“YES” at operation 404), neither the refrigerating chamber R nor the freezing chamber F is in an overload condition (“NO” at operation 406), and the set temperature of the auxiliary freezing chamber CF is not higher than 0° C. (“YES” at operation 412), the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR) and the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) are alternately executed in such a manner that the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR) is first executed, and the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) is then executed (at operation 416). When it is determined that the set temperature of the auxiliary freezing chamber CF is not higher than 0° C. (“YES” at operation 412), when the previous defrosting operation is the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) (“YES” at operation 404), and neither the refrigerating chamber R nor the freezing chamber F is in an overload condition (“NO” at operation 406), the amount of frost on the surface of the auxiliary freezing chamber evaporator 206CF is small because both the internal temperature of the auxiliary freezing chamber CF and the temperature of the auxiliary freezing chamber evaporator 206CF are not higher than 0° C., and thus, the difference therebetween is small. Accordingly, the basic defrosting operation mode of R/CR→F/CF→R/CR→F/CF is executed in such a manner that the defrosting operation next to “F/CF” in the basic defrosting operation mode of R/CR→F/CF→R/CR→F/CF, namely, the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR), is first executed, and the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) is then executed.

On the other hand, when it is determined in the previous defrosting operation determining operation 404 that the previous defrosting operation is the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR) (“NO” at operation 404), neither the refrigerating chamber R nor the freezing chamber F is in an overload condition (“NO” at operation 408), and the set temperature of the auxiliary refrigerating chamber CR is not higher than 0° C. (“YES” at operation 418), the simultaneous defrosting operation is executed for all the four storage chambers R, CR, F, and CF (operation 410). When the set temperature of the auxiliary refrigerating chamber CR is not higher than 0° C., when neither the refrigerating chamber R nor the freezing chamber F is in an overload condition, the auxiliary refrigerating chamber CR is used as a freezing chamber. Accordingly, the simultaneous defrosting operation (R/CR/F/CF) is executed for all the four storage chambers, to achieve sufficient defrosting of the overall storage chamber.

On the other hand, when the previous defrosting operation is the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR) (“NO” at operation 404), neither the refrigerating chamber R nor the freezing chamber F is in an overload condition (“NO” at operation 408), and the set temperature of the auxiliary refrigerating chamber CR is higher than 0° C. (“NO” at operation 418), the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) and the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR) are alternately executed in such a manner that the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF) is first executed, and the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR) is then executed (at operation 420). When the set temperature of the auxiliary refrigerating chamber CR is higher than 0° C. (“NO” at operation 418), when the previous defrosting operation is the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR) (“NO” at operation 404), and neither the refrigerating chamber R nor the freezing chamber F is in an overload condition (“NO” at operation 408), means that the auxiliary refrigerating chamber CR is used as a general refrigerating chamber, so that no defrosting operation is required. In this case, accordingly, the basic defrosting operation mode of R/CR→F/CF→R/CR→F/CF is executed in such a manner that the defrosting operation next to “R/CR” in the basic defrosting operation mode of R/CR→F/CF→R/CR→F/CF, namely, the freezing chamber/auxiliary freezing chamber defrosting operation (F/CF), is first executed, and the refrigerating chamber/auxiliary refrigerating chamber defrosting operation (R/CR) is then executed.

As apparent from the above description, an embodiment of the present invention provides a method for controlling a refrigerator having a plurality of storage chambers, which groups a part of the storage chambers, to selectively enable a defrosting operation to be collectively performed only for the grouped storage chambers, or to be simultaneously performed for all storage chambers, thereby minimizing a degradation in the cooling efficiency of the refrigerator which occurs when the defrosting operation is carried out in an independent manner for respective storage chambers.

Although a few embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

1. A method for controlling a refrigerator including a storage space divided into a first storage chamber, a second storage chamber, a third storage chamber, and a fourth storage chamber, the method comprising: executing a simultaneous defrosting operation of all the storage chambers when at least one of the first storage chamber and the third storage chamber is in an overload condition; executing the simultaneous defrosting operation of all the storage chambers when neither the first storage chamber nor the third storage chamber is in the overload condition, and a set temperature of the second storage chamber is not higher than 0° C.; simultaneously executing defrosting operations of the first, second and fourth storage chambers when neither the first storage chamber nor the third storage chamber is in the overload condition, and a set temperature of the fourth storage chamber is higher than 0° C.; alternately executing a defrosting operation of the first and second storage chambers and a defrosting operation for the third and fourth storage chambers when neither the first storage chamber nor the third storage chamber is in the overload condition, and a set temperature of the fourth storage chamber is not higher than 0° C.; and alternately executing the defrosting operation of the third and fourth storage chambers and the defrosting operation for the first and second storage chambers when neither the first storage chamber nor the third storage chamber is in the overload condition, and a set temperature of the second storage chamber is higher than 0° C.
 2. A method for controlling a refrigerator including a storage space divided into a refrigerating chamber, an auxiliary refrigerating chamber, a freezing chamber, and an auxiliary freezing chamber, the method comprising: executing a simultaneous defrosting operation of all the storage chambers when at least one of the refrigerating chamber and the freezing chamber is in an overload condition; alternately executing a defrosting operation of the refrigerating chamber and the auxiliary refrigerating chamber and a defrosting operation for the freezing chamber and the auxiliary freezing chamber when neither the refrigerating chamber nor the freezing chamber is in the overload condition, and a set temperature of the auxiliary freezing chamber is not higher than 0° C.; and alternately executing the defrosting operation of the freezing chamber and the auxiliary freezing chamber and the defrosting operation for the refrigerating chamber and the auxiliary refrigerating chamber when neither the refrigerating chamber nor the freezing chamber is in the overload condition, and a set temperature of the auxiliary refrigerating chamber is higher than 0° C.
 3. The method according to claim 2, further comprising: executing the simultaneous defrosting operation of all the storage chambers when neither the refrigerating chamber nor the freezing chamber is in the overload condition, and a set temperature of the auxiliary refrigerating chamber is not higher than 0° C.
 4. The method according to claim 2, further comprising: simultaneously executing defrosting operations of the refrigerating chamber, the auxiliary refrigerating chamber, and the auxiliary freezing chamber when neither the refrigerating chamber nor the freezing chamber is in the overload condition, and a set temperature of the auxiliary freezing chamber is higher than 0° C.
 5. A method for controlling a refrigerator including a plurality of storage chambers, and a plurality of heaters to defrost the plurality of storage chambers, respectively, the method comprising: determining whether defrosting is required, for each of the plurality of the storage chambers; and selecting, from the plurality of the storage chambers, storage chambers having similar temperature ranges, when it is determined that defrosting is required, and controlling the plurality of the heaters to collectively defrost the selected storage chambers.
 6. The method according to claim 5, wherein the determination of whether defrosting is required for each of the plurality of the storage chambers is based on at least one of a previous defrosting operation for the storage chamber, an overload condition of the storage chamber, and an operation condition of the storage chamber.
 7. The method according to claim 6, wherein the plurality of the storage chambers comprise: a first storage chamber to provide storage in a refrigerating state; a second storage chamber to selectively provide storage in a refrigerating state or storage in a freezing state; a third storage chamber to provide storage in a refrigerating state; and a fourth storage chamber to selectively provide storage in a refrigerating state or storage in a freezing state.
 8. The method according to claim 6, further comprising alternatively executing a defrosting operation for the first and second storage chambers and a defrosting operation for the third and fourth storage chambers when in an alternate defrosting mode; and simultaneously executing a simultaneous defrosting operation for all the first through fourth storage chambers when in a simultaneous defrosting mode.
 9. The method according to claim 8, further comprising: selectively executing one of the simultaneous defrosting mode and the alternate defrosting mode based upon a set temperature of the fourth storage chamber when the defrosting operation for the third and fourth storage chambers was executed in a latest one of previous alternate defrosting modes; and selectively executing one of the simultaneous defrosting mode and the alternate defrosting mode based upon a set temperature of the second storage chamber when the defrosting operation for the first and second storage chambers was executed in the latest previous alternate defrosting mode.
 10. The method according to claim 9, wherein the alternate defrosting mode is to alternately execute the defrosting operation for the third and fourth storage chambers and the defrosting operation for the first and second storage chambers when the fourth storage chamber is used to provide storage in a freezing state, or when the second storage chamber is used to provide storage in a refrigerating state.
 11. The method according to claim 10, further comprising: executing the defrosting operation for the third and fourth storage chambers in the alternate defrosting mode next to the latest previous defrosting mode when the defrosting operation for the first and second storage chambers was executed in the latest previous defrosting mode; and executing the defrosting operation for the first and second storage chambers in the alternate defrosting mode next to the latest previous defrosting mode when the defrosting operation for the third and fourth storage chambers was executed in the latest previous defrosting mode.
 12. A refrigerator comprising: a plurality of storage chambers to store food therein; a plurality of heaters to defrost the plurality of storage chambers, respectively; and a controller to determine whether defrosting is required for each of the plurality of storage chambers, to selectively group storage chambers together which have a same temperature range and to control the heaters to collectively defrost the grouped storage chambers when it is determined that defrosting is required.
 13. The refrigerator according to claim 12, wherein the controller enables a defrosting operation to be simultaneously performed for all of the storage chambers, to thereby minimize a degradation in a cooling efficiency of the refrigerator.
 14. The refrigerator according to claim 12, wherein the plurality of storage chambers comprises: a first storage chamber to provide storage in a refrigerating state; a second storage chamber to selectively provide storage in a refrigerating state or storage in a freezing state; a third storage chamber to provide storage in a refrigerating state; and a fourth storage chamber to selectively provide storage in a refrigerating state or storage in a freezing state.
 15. The refrigerator according to claim 14, wherein a defrosting operation of the first and second storage chambers and a defrosting operation of the third and fourth storage chambers are alternatively executed.
 16. The refrigerator according to claim 14, wherein a defrosting operation of all of the first through fourth storage chambers are simultaneously executed.
 17. The refrigerator according to claim 12, wherein the determination as to whether defrosting is required for each of the plurality of storage chambers is based upon at least one of a previous defrosting operation for the storage chambers, an overload condition of the storage chambers, and an operation condition of the storage chambers. 